Java Sql Exception After End of Result Set - mysql

Question

My code works fine but when I try to run the code it first shows java.sql.SQLException:After end of result set. I would like to know what is causing this and how to fix this as this is for a graded project.
public GenerateBill()
{
initComponents();
try
{
Class.forName("java.sql.DriverManager");
Connection con=(Connection)DriverManager.getConnection("jdbc:mysql://localhost:3306/bookstore","root","root");
Statement stmt=(Statement)con.createStatement();
String query, product;
query="select * from store;";
ResultSet rs=stmt.executeQuery(query);
while(rs.next());
{
product=rs.getString("productname");
jComboBox1.addItem(product);
}
}
catch(Exception e)
{
JOptionPane.showMessageDialog(null,e.toString());
}
}
When I execute the code a Message Dialog Box shows up first.
And when I click OK, the page I'm trying to make opens and executes normally.
So, I'm confused as to what it means. Also, I'm new to this site, so I don't really know how much of the code I need to add. The rest of the code is for different jButtons. The page is for Generating Bills/Receipts.

Answer 1

There are some parts in your code that could be better. Specifically,
Use com.mysql.jdbc.Driver as your DB is MySQL, instead of java.sql.DriverManager
No need to cast your Connection object.
After /bookstore you could add ?useSSL=false, although it is not mandatory, so something like jdbc:mysql://localhost:3306/bookstore?useSSL=false
Use java.sql.PreparedStatement instead of simply Statement.
Close your connection in a finally block after catch.
Eventually, your code should look somehow like the following,
public GenerateBill() {
initComponents();
Connection con = null;
ResultSet rs = null;
PreparedStatement stmt = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookstore?useSSL=false","root","root");
String query = "select * from store";
stmt = con.prepareStatement(query);
String product;
rs = stmt.executeQuery();
while(rs.next())
{
product = rs.getString("productname");
jComboBox1.addItem(product);
}
} catch(Exception e) {
JOptionPane.showMessageDialog(null,e.toString());
} finally {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (con != null) {
con.close();
}
} catch (Exception e) {
LOG.error("Error closing the connection with the database...");
e.printStackTrace();
}
}
}
Try the above and let me know if it is OK. If not, please post the whole exception to see what causes the issue.